Airport runway light



3 Sheets-Sheet l Nov. 27, 1962 c. J. MCDONALD AIRPORT RUNWAY LIGHT Original Filed July 17, 1957 c a 15 m J E a lllvillllll ||I|||I Nov. 27, 1962 c. J. M DQNALD 3,066,217

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Nov. 27, 1962 c. J. MCDONALD AIRPORT RUNWAY LIGHT 5 Sheets-Sheet 3 Original Filed July 17, 1957 United States Patent N 6 Claims. c1. 2aa 1.2

This invention relates to a lighting apparatus and more particularly to lighting apparatus particularly adapted for use in an airport runway lighting system.

This application comprises a division of my copending application Serial No. 672,049, filed July 17, 1957, now abandoned.

It is the general object of the present invention to produce a new and improved lighting apparatus of the character described.

It is a more specific object of the present invention to provide a lighting apparatus suitable for installation on or adjacent the runways of an airport and which is capable of producing a light beam of relatively high intensity directed in part on the runway surface and in part at a small angle above the horizontal so as to be clearly visible to an approaching aircraft.

Among the features of the present invention is the pro- 'vision of a runway lighting apparatus which may be mounted so as to be almost flush with the surface of the runway so as to present no danger to an aircraft should the lighting apparatus be contacted by one of the wheels of the airplane. In addition, the apparatus is sturdily constructed so as to be capable of bearing the load imposed upon it by an aircraft running over it.

Another feature of the invention is the provision of a runway lighting apparatus having new and improved means for adjusting the direction of the light beam relative to the vertical axis of the apparatus.

A further feature of the invention is the provision of a fixture cover construction having inexpensive means for readily compensating for errors in installation of the fixture housing to provide a desired direction of light output.

Still another feature of the invention is the provision of such runway lighting apparatus permitting facilitated maintenance such as relamping while assuring the reassembly of the apparatus in the desired light direction arrangement without laborious reaiming.

A still further feature is the provision of such a run- Way lighting apparatus wherein the adjusting means is arranged to have effectively minimized interference with the light beam while yet the overall height and top profile slope of the apparatus is effectively minimized.

Still another feature. is the provision of such a runway lighting apparatus having new and improved cover securing structure.

A further feature of the invention is the provision of such cover securing structure permitting ready selective aiming of the output light beam in any one of a plurality of directions as desired.

Other and further features of the invention will be readily apparent from the following description and drawings in which:

FIG. 1 is a side elevational view showing the apparatus of the present invention installed on an airport runy;

FIG. 2 is an enlarged vertical view of the apparatus shown in FIG. 1 and taken along the line 2-2 of FIG. 3; FIG. 3 is a top plan view of the runway lighting system of the present invention;

FIG. 4 is a horizontal sectional view taken along line 44 of FIG. 2;

3,066,217 Patented Nov. 27, 1962 FIG. 6 is an end view of the plate of FIG. 5; and

FIG. 7 is a view of one of the prisms used in the apparatus of the invention.

While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will hereafter be described in detail one embodiment with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated. The scope of the invention will be pointed out in the appended claims.

As shown in FIG. 1, the lighting apparatus 10 of the present invention is particularly adapted to be mounted almost flush with the surface 11 of an airport runway. The lighting apparatus comprises a top cover plate 12 suitably secured to the rim 13 of a substantially cylindrical housing 14 with the latter being implanted beneath the surface of the runway so as to be below ground.

As best shown in FIGS. 2, 3 and 4, the cover plate 1.2 is generally circular in plan and includes an outer portion 15 secured by means of bolts 15a to an inner clamp ring 15b which is adjustably clamped to rim 13 by a partially overlying interclamp ring 15c, in turn secured to rim 13 by suitable bolts 15d. More specifically, as clearly shown in FIGS. 2, 3 and 4, inner clamp ring 15d includes a lower, radially outwardly projecting annular flange portion 15a clampingly engaged by a complementary, upper, radially inwardly projecting annular flange portion 15 of the outer clamp ring 150. Cover 12 is provided with a plurality of holes 12a through which bolts 15a freely pass to be threaded into corresponding threaded holes 15g in inner clamp ring 1511. Outer clamp ring 15c is provided with a plurality of holes 1511 through which bolts freely pass to be threaded at corresponding threaded holes 1311 in rim 13.

Cover 12 further includes an integral downwardly depending annular portion 16 and a top portion 17 extending upwardly above the outer portion 14 a short distance. The top portion 17 is, as previously noted, an integral portion of the cover plate and as the latter is made of relatively heavy metal, the top portion is provided with suflicient strength so as to be capable of bearing loads imposed upon it by aircraft wheels running over the lighting apparatus.

The top portion 17 extends across the upper surface of the cover plate from side to side thereof so as to provide on opposite sides of the top portion light pathways indicated as 18 and 1%. it will be noted that the top portion 17 overlies a pair of openings 20 and 21 extending through the cover plate. These openings are generally rectangular in shape as indicated on FIG. 4 and provide recesses to receive a pair of reflecting prisms 22 and 23. The prisms are held in the recesses by a positioning plate 24 secured by screws 25 to the underside of the cover plate 12. The positioning plate 24 is provided with planar surfaces 2s and 27 upon which the lower faces 28 and 29 of the prisms may rest so as to assure the proper alignment of the prisms within their respective recesses. The positioning plate 24 is, of course, also provided with rectangular openings 30 and 31 immediately adjacent the planar surfaces previously mentioned. If desired, a color filter 32 may be secured by means of clips 33 and 34 to the underside of the positioning plate so as to impart a color to the light emitted from the lighting apparatus.

Beneath the positioning plate is a light source in the form of a filament-type lamp 35 having a convex lens 36 and a parabolic reflector 37. Electrical leads 38 extend through a suitable opening 39 in the side of the housing 14 for the purpose of supplying electricity to the lamp. Suitable brackets 40 and 4-1 secured to the C) underside of the cover plate support the lamp within the housing in the position shown.

The prisms 22 and 23 are, as previously mentioned, capable of both reflecting and refracting light from the source. As illustrated in FIG. 7, the lower face 29 of the prism is arranged to be located generally in a horizontal plane, but the front or emitting face of the prism 43 is not at right angles to the face 29 but, on the contrary, confronts the light pathway 19 and hence the runway at an angle of less than 90 relative to the horizontal. In the embodiment illustrated, the emitting face is at an angle of 60 relative to the horizontal. The third hypotenuse face 44 of the prism is not at an angle of 45 relative to the face 29, as is common in most reflecting prisms, but rather is at an angle of more than 45 relative thereto, i.e., approximately 52. Thus, li-" ht entering the horizontal face 29 is reflected from the hypotenuse face 44 so as to travel in a direction at an angle of approximately l4 above the horizontal but on emerging from the front face 43 is refracted downwardly to approximately 4 above the horizontal and, thus, leaves the prism along a path tilted slightly upwardly relative to the horizontal.

It will be noted that the top portion 17 is provided with edges 45 and 46 which overlie the tops of the prisms 22 and 23 and, thus, protect the prism from damage. Cementitious material 47 between the faces of the prisms and the cover plate provides a weather-tight seal around the prisms so that no further or additional weather-tight cover need be provided for the openings 20 and 21 in the cover plate.

It will .be noted that the openings 26) and 21 in the cover plate are positioned on either side of the center thereof and, thus, on either side of the axis of the parabolic reflector 37. The illustrated positioning of the openings and hence of the prisms mounted therein cates the faces 28 and 29 of the prisms in the areas of greatest light intensity, particularly where the lamp 35 is of the locomotive headlight variety which produces an intense beam of relatively parallel light.

It will also be noted that the prisms 22 and 23 are not precisely parallel to each other in the embodiment of the invention illustrated. Thus, the fixture shown in the drawings is designed to be installed along one edge of a runway and the prisms are so canted as to direct their light towards the center line of the runway. For center line runway installation, the prisms would, of course, be parallel to one another.

In installing lighting apparatus 10, the threaded holes 13a in rim 13 need not be aligned in any particular manner relative to the driveway as the cover plate 12 is readily adjusted to direct the light emitted from the prisms 22 and 23 in the desired direction. More specifically, housing 14 is installed with rim 13 substantially flush with the ground. Rings 15b and 150 are installed on the flange with bolt 15d loosely threaded into flange holes 15a permit-ting sliding movement of inner ring 15b concentrically within outer ring 15c. The cover plate 12 is then secured to ring 15b with bolts 15a and adjusted to the desired angular position wherein the light emitted from the prisms 22 and 23 is directed as desired. The cover is then removed by removing bolts 15a, and bolts 15d are tightened to force outer ring flange portion 15 tightly downwardly against inner ring flange portion 15e and clamp the inner ring securely to rim 13 in this angular position. Cover 12 is then reinstalled and bolts 15a turned down tightly in inner ring threaded holes 15g whereby the cover is firmly secured in the selected position. Should it be desired to remove the cover for any reason, such as replacement of lamp 35, the cover may be readily removed simply by removing bolts 15a and, upon completion of the relamping operation, resecured in the selected arrangement by retightening of bolts 15a. Thus, it may be seen that the novel securing means of lighting apparatus 10 permits ready and accurate positioning of the cover while yet facilitated removal and reinstallation in the desired position may be effected without laborious realigning of the apparatus.

The optical system of the lighting apparatus is designed to direct a portion of the light onto the runway surface and a portion along a beam extending upwardly toward approaching aircraft. Thus, the pilot is able to see not only the surface of the runway, but, particularly with the flat approaches utilized by jet aircraft, the pilot is also guided in part by the elevated beam of light emitted by the prisms.

While the emitting face 43 is arranged in the manner described in order to provide the necessary optics for the system, an incidental advantage to the sloping face is the fact that it provides a slantin runoff for rain water and the like. As previously noted, the cover plate is of heavy metal construction and it is arranged to be in heat transfer relationship to the lamp 35 not only for the purpose of conducting away from the lamp and housing a portion of the heat generated, but also by virtue of being heated thereby to melt away any ice or snow which might otherwise tend to accumulate on the cover and hence to obscure the light emitted from the prisms. The housing, together with the cover plate and prisms mounted therein, provide a weather and watertight enclosure so that maintenance problems are reduced to a minimum. By simply removing the cover plate, all parts of the apparatus subject to wear or requiring occasional replacement are made accessible and, thus, a minimum 'of labor is required for normal upkeep. The particular configuration of the prisms chosen for this application produces a higher degree of light transmission and emission along a desired path than could be obtained with simple reflecting prisms.

I claim: I

1. Enclosure means for use in a runway lighting apparatus, comprising: a housing having an open upper end defined by an annular flange; a cover extending across said upper end of the housing and having a periphery overlying said flange; a first ring interposed between said flange and cover periphery and having a radial projection juxtaposed to the flange and extending upwardly less than the thickness of the ring; means removably securing said cover periphery to said ring in one angular position relative to the axis of said ring; a second ring interposed between said flange and cover periphery and having a radial projection juxtaposed to the cover periphery and extending downwardly to engage said first ring projection; and means removably securing the second ring to the housing flange and clamping said first ring to said flange in any one of a plurality of angular positions relative to the axis of the flange.

2. The enclosure means of claim 1 wherein the last named means comprises a plurality of bolts extending through said second ring and secured to said flange, said second ring having corresponding recesses to receive the heads of the bolts.

3. Enclosure means for use in a runway lighting apparatus, comprising: a housing having an open upper end defined by an annular flange; a cover extending across said upper end of the housing and having a periphery overlying said flange; a first ring interposed between said flange and cover periphery and having an outwardly extending radial projection juxtaposed to the flange and extending upwardly less than the thickness of the ring; means removably securing said cover periphery to said ring in one angular position relative to the axis of said ring; a second ring interposed between said flange and cover periphery and having an inwardly extending radial projection juxtaposed to the cover periphery and extending downwardly to engage said first ring projection; and means removably securing the second ring to the housing flange and clamping said first ring to said flange in any one of a plurality of angular positions relative to the axis of the flange.

4. Runway lighting apparatus comprising: a generally cylindrical weather-tight housing to be implanted adjacent an airport runway with an upper edge defined by an annular flange substantially flush with the surface of the runway; an upwardly directed light source in the bottom of the housing; a relatively heavy, metal cover plate having a periphery overlying said flange of the housing, said cover plate having a load-bearing, top portion spaced above the rim and extending across the cover plate to define light pathways on opposite sides thereof, there being a pair of openings in the cover plate below the top portion and extending therethrough; a first ring interposed between said flange and cover plate periphery and having a radial projection juxtaposed to the flange and extending upwardly less than the thickness of the ring; means removably securing said cover plate periphery to said ring in one angular position relative to the axis of said ring; a second ring interposed between said flange and cover plate periphery and having a radial projection juxtaposed to the cover plate periphery and extending downwardly to engage said first ring projection; means removably securing the second ring to the housing flange and clamping said first ring to said flange in any one of a plurality of angular positions relative to the axis of the flange; and a pair of reflecting prisms mounted one in each of said openings in weather-tight relationship with the respective sides of said openings, each of said prisms having one face confronting the light source and having another face confronting a difierent one of said light pathways.

5. Runway lighting apparatus comprising: a generally cylindrical weather-tight housing to be implanted adjacent an airport runway with its upper edge defining a flange substantially flush with the surface of the runway; an upwardly directed light source in the bottom of the housing; a relatively heavy, metal cover plate having a rim overlying said flange, and an integral, load-bearing, top portion spaced above the rim and extending across the cover plate to define light pathways on opposite sides thereof, there being a pair of openings in the cover plate below the top portion and extending therethrough; a first ring interposed between said flange and cover rim and having an annular radially outer edge surface provided with a first portion juxtaposed to the flange and a second portion spaced from the flange and having a diameter smaller than the diameter of the first portion; a second 4 ring interposed between said flange and cover rim and having a radially inner edge surface complementary to and engaging said edge surface of the first ring; means removably securing said cover rim to said first ring with said first portion of the edge surface of the first ring underlying the second portion of the edge surface of the second ring; and means removably securing the second ring to the housing flange to clamp the first ring to which the cover plate is secured to said flange in any one of a plurality of angular positions relative to the axis of the flange; a positioning plate removably secured to the lower surface of the cover plate within the housing, said positioning plate having openings therein registering with the openings in the cover plate and having prismsupporting planar surfaces adjacent its openings; and a pair of reflecting prisms supported on said planar surfaces and in weather-tight relationship with the respective sides of said openings, each of said prisms having one face confronting the light source and having another face confronting a different one of said light pathways.

6. Enclosure means for use in a runway lighting apparatus comprising: a housing having an open upper end defined by an anular flange; a cover extending across said upper end of the housing and having a periphery overlying said flange; a first ring interposed between said flange and cover periphery and having a stepped annular edge surface; a second ring interposed between said flange and cover periphery and having a stepped edge complementary to and engaging the stepped edge surface of the first ring; means removably securing said cover periphery to one of the rings; and means removably securing the other ring to the housing flange to clamp said one ring to said flange in any one of a plurality of angular positions relative to the axis of the flange.

References Cited in the file of this patent UNITED STATES PATENTS 2,352,801 Rolph July 4, 1944 2,412,603 Dauphinais Dec. 17, 1946 2,628,739 Vischer Feb. 17, 1953 2,750,488 Van Dusen June 12, 1956 2,848,597 Kottnerus Aug. 19, 1958 FOREIGN PATENTS 730,227 Great Britain May 18, 1955 759,848 Great Britain Oct. 24, 1956 

